Apparatus for testing gas



May 31, 193s. G, RAYMOND A 2,119,288

APPARATUS FOR TESTING GAS Filed June 8, 1956 Gwyn/7e Raymond B Y l a I WW Y Patented May 31, 1938- UNITED STATES PATENT OFFICE Application June8, 1936, Serial No. 84,130

7 Claims.

' This invention relates to an apparatus for de termining liquid andsolid matter entrained in as, as for example the amount of oil remainingin gas discharged from a separator, gasoline- 10 carried in the gas, andthe separation should be accomplished without aid of temperature changeor appreciable change of pressuraso that the gas discharged therefromis' entirely free from oil, water, and other impurities.

carried ofi with the gas. For example, if a well is flowing fifteenmillion cubic feet of gas per day and loosing six gallons of oil permillion feet of gas, the loss in oil is over two barrels per day, 20 andwhile it will be noted that the loss in 011 represents an appreciableamount, it is very minute in proportion to the gasflow Therefore,

to accurately determine the amount of oil carried off with the gas, themeasuring apparatus must 25 ,be one of precision, and tial care.

It is, therefore, the principal object of present invention, to providefor accurately ascertaining the tree liquids and solids contained inoperated with substan- 30 a gas stream' in a facile manner.

It is also an object of the invention to collect any suspended materialthat might be contained.

in a gas stream concurrently with measuring. the flow volume of saidstream.

In accomplishing these objects, I have provided improved details ofstructure, the preferred. form of which is illustrated in theaccompanying a drawing wherein:

- Fig.1 is si -perspective view of an oil and gas 40 separator equippedwith my improved apparatus for determining the oil content of the gasstream discharged therefro Rig. 2 is'a longitudinal section through thetesting apparatus. 45

Fig. 2.

Fig. 4 is an enlarged detail section through the inlet end of the filterelement.

Pig. 5 is a detail section. particularly illus- 50 trating the tube fordiverting a portion of the gas stream into the testing apparatus.

Referring more in detail to the drawing:

l designates a separator'whichis connected with the flow line I of anoil well (not shown), 55 and wherein the natural gas content of the wellIf the equipment is 15 not operated efllciently, much oil is lost bybeing Fig. 3 is a cross-section on the line 8-! o! flow is separatedfrom the oil, water, and impuri: ties that may be contained in the flow.After separation, the gas is carried oil. from the upper end of theseparator through a gas discharge line 3, leading to a source ofdisposal.

In separation of this gas, the efliciency ofseparation may beascertained by determining the quantity of liquid oil spraycarried overwith the gas, and I have provided for catching the free liquid oil,andother suspended material, by diverting a 10 portion of the gas flowthrough a filtering agency.

Since the oil and gas aresimilar in constituents but different in phaseor state, any temperature change and/or pressure change will efiect. theratio of the oil and gas content of the stream, that is,as thetemperature increases and/or pressure decreases, oil will-pass to thegas state or condition, and as the temperature drops and/or pressureincreases the gas begins changing to the oil phase. Therefore, in orderto determine accurately the amount of suspended oil left entrainedby thegas, it is essential that the filtering operation be carried on under asnearly as possible the actual working conditions of the separator. It isalso necessary that the temperature, pressure, and volume of gas flowingfrom the separator be determined concurrently with filtering of ameasured sample of the flow. Heretofore this has been a difficultmatter, but I have provided a method wherein these calculations arereadily accomplished, as now to be described.

The gas discharge line 1 is drilled and tapped as close to the separatoras convenient, for example at 4, for the insertion of an intemaliythreaded bushing 5. Threaded in the bushing s is a nipple 6, carrying agate valve 1, having its discharge side provided with a similar nipple 8that is connected to a stufling box I through a reducer fitting It. Thestufllng box 9 is provided with an axial channel ll extending through anexternally threaded neck It, on which is threaded a packing gland II fortightening a packing ring l4 about a draw-ofl-tube i5.

The draw-oil tube It is of suitable diameter to he slid through anopening il in the gland, and through the packing ring it into thechannel.ll, and has a closed, rounded end l1 provided with one or moreinlet openings l8, extending through the wall of the tube-in the-mannerof a Pitot tube. The opposite end of the tube I5 is connected by a unionI! with a nipple 2|,

connected to the inlet side of a shut-off valve 2|. The outlet side of.the valve II is provided with a nipple 22 that is screwed into theinlet fitting 55 23 of a gas sampler 24, embodying the features of thepresent invention.

The sampler 24 includes a cylindrical outer casing 25, having a closedend 26 carrying the The fitting 23 is fixed to the end wall 25 of thecasing 25 in an internally threaded flange 30. Fixed within a bore 3! ofthe fitting is a tube 32, having one end aligning with the nipple 22,and its opposite end extending through a packing recess 33 in thefitting, and through an opening 34 in the end wall that conforms indiameter with the opening of the flange 30. Positioned in the packingrecess is a packing ring 35 for encircling the tube 32, and to form aseal for the end of a filter cartridge, later described.

Fixed to the inner face of the wall 25 is a flange 35, having aninternally threaded opening 31 aligning with the opening 34, and inwhich is threadedly mounted a nipple 38, which carries a casing 39 forthe filter cartridge 40. The cas-' ing 38 includes a sleeve 4i, ofsmaller diameter than theinner diameter of the casing 25,

and of shorter length, to freely accommodate a. head 42 for closing ,theend thereof. The head 42 is welded directly to one end of the sleeve 4!,and has an internally threaded opening for accommodating the nipple 38to secure the cartridge casing concentrically within the casing 25. Thenipple 38, after being screwed into the f head 42, is then finallywelded therewith.

Inserted within the opposite end of the sleeve is the filter cartridge40, which preferably includes a glass cylinder 45, having a reduced neck46 at one end, of suitable diameter to freely pass through the nipple 35so that the end there of sealingly engages the packing ring 35. Thereduced portion of the cartridge also forms an annular shoulder 41 tosealingly engage against the packing ring 48 that is mounted in therecess of the head 42. The opposite end of the filter cartridge projectsfrom the free open end of the sleeve 4|, and is provided with a bellflange 49 to receive a conical-shaped stopper 50. The head 43 includes afiat bar of substantially greater length than the diameter of the sleeve4|, and has openings to engage over the threaded ends of draw bolts 5|that are anchored in a fi'ange 52 fixed to the periphery of the sleeve4|, the draw bolts 5i being provided with nuts 53 whereby the head maybe drawn against the stopper to wedge it fluid tight within the belledend of the filter cartridge. The head 43 is provided with an opening 54that communicates with the interiorof the cartridge through an aligningbore 55 in the stopper 53. I

It is thus apparent that when the stopper is drawn in sealed engagementwith. the open end of the filter cartridge, the pressure applied by thenuts 53 also causes the cartridge to be tightly sealed against thepacking ring 35, and when the nipple 33 of the shell 4| is screwed homein 35, the small end of the cartridge slides over tube 32 and vseatsagainst the packing ring 35.

Contained within the filter cartridge is a filterlng material 55,preferably consisting of glasswool,-rock-wool, or similar material, thatdoes not cause absorption of gases, but which filters from the gas allentrained liquids and solids.

The removable head 23 of the casing 25 is provided with a threadedopening 51 which aligns with the axis of the orifice 54, to mount anipple 58 that connects with the inlet side of a needle valve 59, havingits outlet side connected by a nipple 50 with a back pressure chamber61. The back pressure chamber includes a cylindrical casing 62 having athreaded outer end 63 for mounting an orifice adapter cap 64 having anorifice plate seat 55. Removably inserted in the seat 65 is an orificeplate 66, having a criti-' cal flow orifice 61 therein for regulatingflow of gas from the back pressure chamber 6|. The orifice plate 56 isremovably retained in its seat by a suitable fastening device 68.

In order to obtain the temperature of the gas within the casings 25 and62, they are provided with wells 59 and I3 in which thermometers ii and12 are inserted to record the temperatures therein, as later described.The casings are also provided with pressure gauges l3 and 14respectively, wherew'ith pressure of the gas in the chambers may beindicated.

The apparatus thus described may be supported in aligned position withinthe valve 1 on a trestle 15, of any suitable construction.

The gas discharge line is also drilled and tapped beyond the valve 1, asat 16, to provide for the insertion of a Pitot tube 11, or similarapparatus, wherewith the fiow volume of the gas through the line 3 maybe determined in a well known manner.

In using an apparatus constructed as described, the cylinder portion ofthe filter cartridge is filled with a quantity of filter material, suchas glass-wool, rock-wooLor the like, that is nonabsorptive, after whichthe stopper is inserted in the cartridge, and the cartridge containingthe filtering material is accurately weighed. The weighed cartridge. isthen inserted through the open end of the casing 25, so that the neckthereof sets against the packing rings 35 and 48. The plate 43 is placedagainst the stopper 50, and the stopper'is inserted in the open end ofthe cartridge and clamped in position by applying the nuts 53. The tubei5 is inserted through the stuifing box 9 and on into the pipe 3,through the valve 1 which has been opened. The gland I3 is thentightened and the tube i5 is connected to pipe 20 by the union 18. Thetube i5 is marked so that the aperture or apertures at the end extendinginto pipe 3 may be turned up-stream.

A portion of the gas stream is then diverted through the tube I5, valve21, and through the filtering material, into the interior of the casing25 where the pressure thereof is indicated by the gauge 13, and thetemperature by the thermometer ll. Upon opening the needle valve 59, thegas will flow into the back pressure chamber and through the orifice 51of the plate 66. The rate of flow of gas through the tester is regulatedto pass the maximum amount of gas at a reasonable low pressure dropacross the filtering cartridge. This is important because if thepressure drop acrossthe filter is great, the high velocity of the gaspassing through the filter will result in rivers" or small passagewaysbeing opened through the filtering medium, and should this occurpractically all the filtering efiiciency would be lost. The prmsure dropis determined by the size of the tubing l5, cartridge 40 and the orifice51, which are so proportioned that when the cartridge 4| is packedinproper manner with glass wool or the equivalent, the pressure drop willbe the desired amount. The temperature and presa,1i'e,ase I sure of thegas in the back pressure chamber is indicated by the pressuregauge I4and thertained by the Pitot tube I1. Thus the relative' proportion ofth'e'fiow through the filtering niedium and the flow through thedelivery pipe may be readilycalculated. The gas, upon flowing through.the filtering cartridge, is relieved of any entrained liquid which istrapped on the filtering media. After the fiow has continued for adefinite period the valve 2| is closed.

At the close of a run, valve ii is closed, and the back pressure chamberis disconnected by removing bolts 29. The nuts 53 are then loosened toallow the bar 13 to beswung aside, whereafter the cartridge 40 isremoved. The filtering car.- tridge containing the filtering material isthen carefully weighed to determine the change in weight, whichrepresents the weight 0! the material that has been filtered from thatportion of the gas stream that hasbeen measured through the orifice 61for the recorded time interval. Then, since the temperature and pressureat which the filtered material was collected are knowmand since the sizeof the orifice is known, the volume of gas flowing through the filteringdevice, corrected to maintain discharge gas con.-

' ditions, can be readily calculated. With the weight of theentrained'oil, liquid, and solids that have been removed fromthis volumeof gas and with the total volume of gas flowing from the separatorknown, the amount of oil, liquid and solid matter passing with the gasfrom the separrator is readily calculated. 0 s

It is thus apparent that the measurement of .the respective fiowvolumes, temperatures andpressures are taken simultaneously with thefiltering out of the foreign material, so that calculation of the amountof oil lost in extremely large gas volumes is exceptionally accurate.

What I claim. and desire to secure by Letters Patent is: I

I. In an apparatus of the character described, a gas sampler includingan outer casing, a car- I tridge removably supported in the casing forconfining a body of filtering material, means for passing gas throughthe filtering material, means con-,

nected with the casing for indicating temperature'and pressure of thegas passed thi'ough the filtering material means associated with saidsampler .for maintaining a definite flow of gas through the filteringmaterial, a back pressure chamber connected with theoutlet side of thecartridge, means controlling fiow 01' gas from the back pressurechamber, and means indicating temperature and pressure of the gas insaid back pressure chamber. 1

54. In an appa i nite flow of. gas through the filtering material, abackpressure chamber connected with said fiow control means and having a gasoutlet, an orifice plate controlling said outlet, and means fordetermining temperature and pressure of the gas in said back pressurechamber. I

3. In an apparatus for determining the amount of liquid and solid matterentrained in a gas includiri'g a casing having inlet and outletconnections, a packing in the inlet connection, a car-- tridgecontaining shell oi smaller diameter than the casing to provide anannular gas containing chamber, means connecting the shell with thecasing concentrically with the inlet connection, a gasket ring in theshell, a filtering cartridge having a reduced neck portion for engagingthe packing at the inlet connection and forming an annular seat engagingthe gasket ring, afplug clos-- ing the opposite end of-thefilteringcartridge and having an outlet opening into.the chamber, means connectedwith the shell for retaining the plug, means for admitting gas to theinlet connection, and means for discharging the gas. at predeterminedvelocities through the outlet connection.

ratus for determining the amount of liquid and solid matter entrained ina gas including a casing having inlet and outlet connec- "tions, apacking in the inlet connection, a cartridge containing shell of emallerdiameter than .the casing to provide an annular gas containing chamber,means connecting the shell with the casing concentrically with the inletconnection, a gasket ring in the shell, a filtering cartridge having areduced neck portion for engaging thepacking at the inlet connection andforming an annular seat engaging the gasket ring, a plug closingtheopposite end of the filtering cartridge and having an outlet openinginto the chamber,

means connected with the shell for retaining the plug, means foradmitting gas to the inlet connection, a back pressure chamber, valvedmeans connecting the back pressure chamber with the outlet connection,and an orifice plate connected with the back pressurechamber fordischarging gas from the back pressure chamber.

5. In an apparatus ior determining the amount of liquid and solid matterentrained in a gas including an outer casing having inlet and outletconnections, a cartridge in the casing including a shell formed ofmaterial impervious to the pas-- sage oi gas and having an inletsealingly engaging with said inlet connection and having an outlet atits opposite end, a filtering material in said shell for trapping andretaining any liquid and solid matter entrained in the gas. saidcartridge being spaced from the walls of the outer casing to form a gaschamber, means for maintaining a definite pressure in said chamber tomaintain a definite fiow of gas through the filtering material, and,means connected with said outlet connection. for deterini the volume ofgas passed through the filtering material.

6. Inan apparatus for determining the amount or liquid and solid mattercontained in gas including a casing having gas inlet and outletconnections, a cartridge contained in said casing to the e or gas andhaving an inlet connected .with said inlet connection and a restricted.outlet opening to the interior of theming, a filtering material in theshell for pping and retaining the liqui d and solid. tterentrained-ingas delivered throu'gh. said inlet eonnectiommeans for controllingpressure oi gas in including a shell formed of material impervious saidcasing to maintain a definite flow of gas through the filteringmaterial, a back pressure chamber connected with said control means andhaving an orifice plate for controlling flow of gas from the backpressure chamber, and means for indicating the pressures andtemperatures of the gas passing through said outer casing and in saidback pressure chamber '7. In an apparatus of the character described, afiltering cartridge, means for delivering gas to the filteringcartridge, means for maintaining a predetermined flow of gas through thefiltering .cartridge, 9. back pressure chamber for receivi s deliveredfrom the filtering cartridge to the back in pressure chamber.

: GWYNNE RAYMOND.

